Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
Strings in C#: Interpolation, StringBuilder and the Turkish I Trap
Immutability of strings in C#, interpolation and format specifiers, escape sequences and verbatim strings, commonly used methods, the measured memory difference with StringBuilder, StringComparison and the Turkish I/ı/İ trap.
Numbers and Arithmetic in C#: int, double, decimal and Overflow
Integer division and the remainder in C#, choosing between int, long, double and decimal, why 0.1 + 0.2 isn't 0.3, decimal for money, overflow and checked, dividing by zero, the Math class and the banker's rounding trap.
Variables and Data Types in C#: var, const and Literals
Statically typed variables in C#, the sizes and ranges of the built-in types, what var really does, literal suffixes and the compiler errors around them, const and C# 10's constant interpolated strings, default values and .NET naming conventions.
Installing C# and Your First Program: dotnet new console and the Project File
Installing the .NET 10 SDK, the first project with dotnet new console, top-level statements and the Main the compiler generates, TargetFramework, ImplicitUsings, Nullable and LangVersion in the csproj, dotnet run and build, choosing an IDE, and reading your first compiler error.
What Are C# and .NET? Language, Platform and Versions
The line between C# and .NET: the compiler, IL and JIT, the CLR, the BCL, SDK versus runtime, the move from .NET Framework to .NET, the LTS/STS support calendar, how C# and .NET versions pair up, and the plan for the seven-series C# family.
Dapper.AOT: Dapper with Source Generators, Interceptors and Native AOT
Why does vanilla Dapper blow up even under dotnet run once PublishAot is on? Generating the code at build time with Dapper.AOT 1.1.0: [module: DapperAot], InterceptorsNamespaces, the generated interceptor code, Native AOT publish and a startup time going from 49.8 ms to 4.3 ms, type handlers as attributes, the DAP analyzers and limitations such as QueryMultiple.
Dapper Performance: Query Cache, GetRowParser and Bulk Alternatives with SqlBulkCopy and COPY
What Dapper's query cache holds and why it draws a saw blade, when CommandFlags.NoCache is needed, choosing a type per row with GetRowParser, and for the bulk operations Dapper lacks: a transaction on SQLite, SqlBulkCopy on SQL Server and COPY on PostgreSQL, all with real measurements, closing with BenchmarkDotNet.
Dynamic SQL with Dapper: SqlBuilder, Safe Filters and Contrib, Dommel, Dapper Plus
Building optional filters without string concatenation: Dapper.SqlBuilder's templates and placeholders, count and page queries from one builder, safe sorting with a whitelist and the OrWhere surprise. Then a balanced look at Dapper.Contrib, Rainbow, Dommel and the commercial Dapper Plus as of November 2026.
Dapper and SQL Server: TVPs, ANSI Strings, {=literal} and Parameter Sniffing
Queries that return the right result but scan the whole index: the implicit conversion nvarchar parameters cause on varchar columns, Dapper's 4000-character rule, IN lists multiplying plans, table-valued parameters, filtered indexes with {=literal} and parameter sniffing, all with real logical-reads measurements.
Stored Procedures with Dapper: Output, Return Value and the Auto-Detection Trap of 2.1.11
SQLite has no stored procedures, so we move to SQL Server in docker: CommandType.StoredProcedure, output and return values with DynamicParameters, how SET NOCOUNT affects Execute, single-word commands mistaken for procedures since 2.1.11, and the function vs procedure difference in PostgreSQL.
Type Handlers and Custom Mapping in Dapper: Guid, DateTimeOffset and CustomPropertyTypeMap
Why does Dapper blow up when reading Guid, DateTimeOffset and TimeSpan on SQLite? We write interpreters with SqlMapper.TypeHandler<T>, see from the source why SetValue is never called, and cover the DateOnly/TimeOnly story of 2.1.86 and column mapping with CustomPropertyTypeMap.
Buffered and Unbuffered Reads in Dapper: Streaming Large Result Sets
We measure the difference between buffered and unbuffered reads in Dapper: an unbuffered result re-running the query on every enumeration, 191 MB versus near-zero memory on a million rows, IAsyncEnumerable streaming with QueryUnbufferedAsync, cancellation with WithCancellation and the disposed-connection trap, all with real output.